Optimal Aeration Management Strategy for A Small-Scale Food Waste Composting

Food waste is a significant contributor to greenhouse gas emissions when it ends up in landfills. Composting is a sustainable solution to this problem, but it requires controlled and continuous airflow for optimal performance. The objective of this study is to investigate the effect of aeration rates and airflow directions on food waste composting using a closed system with forced aeration. Air was entered into the composting vessel in three directions, which were upward, downward, and a combination of both directions. Each direction was run at aeration rates of 0.1, 0.4, and 0.7 L/min. The findings show that the compost pile aerated at 0.4 L/min by using two-directional airflow can reach the thermophilic temperature within half of the day. The compost pile achieved temperature of 40.94°C after 10.5 hours. Although the compost experienced slightly high in moisture loss (4.3%), the compost still attained the standard values for maturity. The compost produced from food waste could be applied in soil to improve its fertility

Korean Red Ginseng Improves Blood Pressure Stability in Patients with Intradialytic Hypotension

Introduction. Intradialytic hypotension (IDH) is a common complication during hemodialysis which may increase mortality risks. Low dose of Korean red ginseng (KRG) has been reported to increase blood pressure. Whether KRG can improve hemodynamic stability during hemodialysis has not been examined. Methods. The 8-week study consisted of two phases: observation phase and active treatment phase. According to prehemodialysis blood pressure (BP), 38 patients with IDH were divided into group A (BP ≥ 140/90 mmHg, n = 18) and group B (BP < 140/90 mmHg, n = 20). Patients were instructed to chew 3.5 gm KRG slices at each hemodialysis session during the 4-week treatment phase. Blood pressure changes, number of sessions disturbed by symptomatic IDH, plasma levels of vasoconstrictors, blood biochemistry, and adverse effects were recorded. Results. KRG significantly reduced the degree of blood pressure drop during hemodialysis (P < 0.05) and the frequency of symptomatic IDH (P < 0.05). More activation of vasoconstrictors (endothelin-1 and angiotensin II) during hemodialysis was found. The postdialytic levels of endothelin-1 and angiotensin II increased significantly (P < 0.01). Conclusion. Chewing KRG renders IDH patients better resistance to acute BP reduction during hemodialysis via activation of vasoconstrictors. Our results suggest that KRG could be an adjuvant treatment for IDH

Sheet metal process machines

Any metals can be formed into flat or thin pieces of varying thickness and geometry.The shaping of the sheet metals is grouped in the sheet metal process.The shaping of selected metal washers is being discussed comprehensively.This research reveals the basic process of metal stamping which include the mechanism of shearing operation.The benefits and drawback of sheet metal process are also being discussed.This research gave a better understanding to the readers on the basic concept of sheet metal process

Subwavelength spatial solitons of TE mode

Abstract The wave equation of TE subwavelength beam propagations in a nonlinear planar waveguide is derived. This equation contains more higher-order linear and nonlinear terms than the nonlinear Schrodinger equation. The analytic solution of TË subwavelength spatial soliton is found to be the same as the conventional spatial soliton in amplitude but different in phase. The numerical results show that the analytic solution is stable.

A Numerical Solution for Broadband PLC Splitter with Variable Splitting Ratio Based on Asymmetric Three Waveguide Structures

A numerical solution for the broadband planar-lightwave-circuit (PLC) splitter with a variable splitting ratio based on asymmetric three waveguides weighted by the Blackman weighting function is designed for passive optical network applications with wavelengths between 1.53 and 1.57 &#181;m. The performance of the proposed splitter is verified using the beam propagation method (BPM). It was found that a polynomial function of the splitting ratios accompanying a geometrical shift can be derived from the proposed splitter. The splitting ratio can be changed from 50:50 to 90:10 with this geometrical shift. The excess loss, crosstalk, polarization dependent loss, and splitting ratio variations against wavelength of the proposed splitter with wavelengths between 1.53 and 1.57 &#181;m are better than 0.139 dB, &#8722;22.75 dB, 0.006 dB, and 0.335%, respectively. Obviously, the proposed splitter with variable splitting ratio retains the advantages of the symmetric design, such as low excess loss, low crosstalk, polarization insensitivity, broadband, and wavelength insensitivity

Theory of mode coupling in a photorefractive crystal waveguide

The mode coupling among guided modes in a photorefractive crystal waveguide is investigated. We derive the coupled equations of guided modes in a photorefractive crystal waveguide. Analytical solutions of the coupled equations are obtained for a two-mode photorefractive crystal waveguide. We also numerically analyze the coupled equations of guided modes in a multimode photorefractive crystal fiber. As a result of the coupling, power may flow to the fundamental mode or the highest-order mode, depending on the direction of the crystal optical axis. In addition, we report an analytical solution of the modal power in core and cladding for all guided HE m and EH m modes for cylindrical fibers made of uniaxial crystals

WDM Soliton Transmission System Using Dispersion Slope Compensators

Abstract-A new scheme of dispersion slope compensator by writing Bragg gratings at different positions in a dispersion compensation fiber is proposed for the wavelength division multiplexing soliton transmission system. This scheme can compensate in-line for the accumulated dispersion of each channel and suppress the dispersive waves which are caused by the incomplete filtering of the signals of the neighboring channels by using Fabry-Perot or Butterworth filters and the different propagating paths of the signals of the different channels in the dispersion slope compensator. Index Terms-Dispersion slope compensation, fiber Bragg grating, optical solitons. T HE wavelength-division-multiplexing (WDM) soliton transmission system is limited by the timing jitter caused by the soliton interactions, the amplifier spontaneous emission (ASE) noise (Gordon-Haus effect), and the unsymmetrical collisions between different channels. By using the dispersion compensation fibers (DCF&apos;s) [1]- In the DSC, some fractional energy of the signal of a channel appears in the neighboring paths because of the incomplete filtering process due to the finite spectral side-level of the optical bandpass filter. This fractional pulse propagates in a different path from the principal pulse. After the DSC the fractional pulses lead or lag behind the principal pulse

Auxiliary Reference Samples for Extrapolating Spectral Reflectance from Camera RGB Signals

Surface spectral reflectance is useful for color reproduction. In this study, the reconstruction of spectral reflectance using a conventional camera was investigated. The spectrum reconstruction error could be reduced by interpolating camera RGB signals, in contrast to methods based on basis spectra, such as principal component analysis (PCA). The disadvantage of the interpolation method is that it cannot interpolate samples outside the convex hull of reference samples in the RGB signal space. An interpolation method utilizing auxiliary reference samples (ARSs) to extrapolate the outside samples is proposed in this paper. The ARSs were created using reference samples and color filters. The convex hull of the reference samples and ARSs was expanded to enclose outside samples for extrapolation. A commercially available camera was taken as an example. The results show that with the proposed method, the extrapolation error was smaller than that of the computationally time-consuming weighted PCA method. A low cost and fast detection speed for spectral reflectance recovery can be achieved using a conventional camera